What is color fastness rating?
Colour fastness is the resistance of a material to change in any of its colour characteristics, to the transfer of its colourants to adjacent materials or both. The other fastness ratings are normally evaluated by the grey scales for bleeding and for fading.
What does lightfastness mean in paint?
Lightfastness – The lightfastness of a paint color or pigment is how permanent it is, or how unaffected it is by light.
What does lightfastness mean in fabric?
Lightfastness typically means the degree and duration to which dye resists fading due to constant light exposure. Simply explained the amount of time your fabric sits in the sunlight before it starts to fade in color.
What is grayscale in textile?
Grayscale is used for assessing the color shading in between products and the customer’s approval sample or among pieces in production. Gray scaling has grades 1-5 and increases by half of the grade (1, 1 1/2, 2, 2 1/2, and so on.) with 5 being the greatest.
What is GREY scale in textile?
Both scales measure color-fastness of textile dyes. Gray Scale for color change indicates the amount of fading or color alteration with environmental exposure or washing, and gray scale for staining indicates the amount of staining of adjacent materials that occurs with washing of a specimen.
What is the best lightfastness rating?
Standards and measure scales
| Description | Measure scales | |
|---|---|---|
| Blue Wool rating | ASTM rating | |
| Very good lightfastness | 6 | II |
| Excellent lightfastness | 7 | I |
| 8 |
How do you measure color fading?
The color of a coating can be quantified by using a colorimeter. The colorimeter measures the spectral energy of light reflected from the coating over the visible spectrum. The instrument then assigns the resultant measurement standard color coordinates on what is known as a color space.
What is good lightfastness rating?
The most well known scales measuring the lightfastness are the Blue Wool Scale, Grey scale and the scale defined by ASTM (American Standard Test Measure). 1 being very poor and 8 being excellent lightfastness. In grey scale the lightfastness is rated between 1–5. 1 being very poor and 5 being excellent lightfastness.
How do you test lightfastness?
At its simplest, this test can be accomplished by applying the material to be tested to a suitable support, cutting the sample in half, and exposing part of the test specimen behind a window that provides as much sunlight as possible, while keeping the other half shielded from all light sources.
What does a grade of 5 Mean on a grayscale?
A value of 5 corresponds to virtually no staining, whereas 1 indicates poor color-fastness.